Internet technology has been growing at an overwhelming pace and has become an essential part of our lives. In particular, Web-based Internet technology gained its popularity for ease of use, ubiquitous connectivity and accessibility to a vast amount of information and services. The advancement in Internet technology makes possible things that were once considered difficult or even impossible. Numerous business models based on the Internet have come and gone, and some are still thriving and deeply integrated into our daily lives and work. One can find such examples in businesses from Internet portals, E-commerce, search engines, forums, online gaming, entertainment, user-created content, social networking services, etc. Particularly, social networking has lately become one of the fastest growing fields in the Internet-based business sector with the advent of new Web technologies, better known as Web 2.0, in addition to the rapid proliferation of high-speed broadband Internet connectivity available for the general public. More and more Internet users can access technology-packed Web sites with little or no knowledge about the technologies on which those Web sites are built. Advanced Web technology has enabled feature-rich and interactive, thus more user-friendly, development of Web sites.
Most of the Internet services strictly rely on online advertisement to generate revenues: the company runs a Web site and receives fees from advertisers to post their advertisements. In return, they show their advertisements on the Web site to visitors. Alternatively, the company may run a Web site that primarily relays a useful piece of information to the users and receives subsidized fees based on the amount of redirected traffic to the host Web sites operated by the fee-paying advertisers. Nevertheless, the more traffic that a Web site generates, the more profitable the Web site is, since it has more exposure to potential customers.